Tuning unit for radio receiving sets



Sept.'1, 1925. 1,552,266

F. C. BRADLEY TUNING UNIT FOR RADIO RECEIVING QTS Filed Feb. 19, 1925 h FRANCOIS L. Bmnmw, ii Since residing- 3i ion in file ccunty 0'? Newton and Staitc Jpgi, imvc inven (i certain iii l'mpmvcmems ailing UIililS f 0? which the his invention YiiiZ'LLQS tuning units for note? for ma in J bIGtHiC-ilfiil xeceivmsc "pc'rtmn, of Kim invention is @rmric ccvicc 5 diameter imc'iccic. ccmbimfi'iozi 0f c meme? usually Tc ccnsici constructed ti'azii; skiii is ciiininaiicci and? uni-3' ccccmcs suiasmnfiaiiy mechanicpcmuicn.

vcntion has pcrticnia? rcfercncc so Of 0 5 it ccniicfiscr, inner coii usually ccnnccic zi in iiic gii i ciicnit a vacuum m c-e m receiving and a feed back coil nsuaii i owed in ii piste circuit 52w same Qu ns L wicm'inn- It is Wei} knc-Wn to *simsc fzunhar with thc that regencra'cim is very fiifficuik 10 commi. Where the appm'a ms cmpioycci may require 21- cc apprcn. mwlicn W the (ms at low freqcncics an cncireiy cnfi creni; arrangemcni cf the coils necessary at higiicr frequencies rin to The fact fimx fliesc higher frequencies inwc a icdcncy ioseiif i'cgcncnh tier: in the grid coil. As mnttcr c"? film's such higher frcqncncfl pmciicaliy no m cncz'ation can empicyefi. Ucimii u grifi nmi picks coiis; of regcnci'ntivc apim'raius are pz'cviiicfi with pumicconfirm, by mcarw which 119 "pm. tion of the piaic coii may 33c ti'ciied to thcrcby 'L Miami; 01? iigcnex=aizicn, films contra; ncccssicqting the timing of two instruments to p'mviic properliiming: ami rcgenecntion at my Wave ici'agth All impm'i'ant object of this invention is accowiingzly Hie provision bi? such an cpparntns wherein the ])ns iti0n of inc pimp coii wirn relation to the QYid coil :mtcmatimliy contmiicd by ihe npm'acicn of iiic ccnflcnscr timing ivhc grid coi'i.

A Sti fur'ihc'r object of bhc invcniion is $9 pm c a min s-i and improvmil apparains of his mbic cf appiica'ticn to any ccilticnsei Whifih might bc dcsirci fcr W acts and mc'sc pmticuiariy ci'abic 5km in imnci'iing' t0 provide a (ievicc that prams-ion m cci'mcctlon i b acrizei a #s, the mimcmi A L' a rci'zm y vac may 33c any suilaiiic pnsfS cicctric Hy connecie i. pixies L 2 zis ccmicnscr ami 1 shaft 0" the ccndcns' cwiaicii ie: a connccici Wi'ah thc mi cz'" 13L ccmicnser 3113" by rciaticn firm 0"; isilc capacity thc cc'nr' Thespcr'cs aw hi1 ncmnai ordinary variable cnndcnc Hie invcnticn in 2110 Way 132166;? wlfih tine apparatus izcz-cinzulc'r In accordance with my inv Vida 21 meta-Hie arm 15' which 1 cncbinding pos 11 of the ccmi: Hie free cnci of which exicnci. from the rcafc'mi pints of a diaaance sufi icim'it to pcimit rcml ingr upon cm? of? a ccii l6 0i. my snimiflc character, T119; coil pmiemb iyg hmvevm', ii? .ti c type QQUFFFLHY] referred ")0 as spider 'wcica The arm being of ccn- (Tm-hing n'iatciciai serves as: a meals 0?? ccitu nesting fillfl: terminal 1'? of ibis coil in the ciatcr of the variabic ccni'i' 'iihc se curing eiemcm diz'ccicd sm'cugh we end of the sc 2:; both am 21- :meacs fez mcchnnicai'ly attaching the arm to thc tic-i1 and him terminal the coil 20 time a l'fiOHD'iTiIEgfOZ an insuiciging 3311x719, (51* free end of which is pmviiicai w ch a 0021i; receiving binding post to which second terminal 21 of tiic coii may he can" ncctmi. The connection of the mm m tnc binding pact 11 is such tiizi'i; the mini rigid in his binciing post.

By mczms of a sec 11d binciing; post 11', an insulating arm is; ccifmcctcc to thc 211 55.

' movable coil to maintain the same in predanamed coil; a sprin urging the second coil toward the first coi and means carried by the rotor shaft and operatively engaging the terminedpositions with relations to the first of the rotary elementto the condenser, the support of the first named coil including means 'for electrically cdi necting one terminal of the coil to one terminal of the condenser.

4. A tuning unit comprising in combination, a rotary interdigitating plate variable condenser including the usual rotor shaft, rear end plate and binding posts carried thereby, a coil supported from one of said binding posts, a second coil supported from a second binding post and in inductive rela tion to the first named coil, the support of the second named coil permitting movement of the coil toward and away from the first named coil, a spring urging the second coil toward the first coil, and means carried by the rotor shaft and operatively engaging the movablecoil to maintain the same in predetermined positions with relation to the first named coil corresponding to given positions of the rotary element of the condenser, the support of the first named coil including means for electrically connecting one terminal of the coil to one terminal of the coni named coil correspondin to given positions denser and having mounted thereon an insu lating supporting arm for the second terminal of the coil.

5. A tuning unit comprising in combination, a rotary interdigitating plate variabie condenser including the usual rotor shaft, rear end plate and binding posts carried thereby, a coil supported from one of said binding posts a second coii supported from a second binding post and in inductive relation to the first named coil, the support at the second named coil ermitting movement of the coil toward am? away from the first named coil, a spring urging the second coil toward the firstcoil, and means carried by the rotor shaft and operatively engaging the movable coil to maintain the same in predetermined positions with relation to the first named coil corresponding to given posi tions of the rotary element of the condenser,

the support of the second named coil ineluding a member stationary witn relation to the condenser and with the binding post, a pivot carried by said. member, an arm mounted for oscillation upon the pivot and upon the free end of which the coil is adjustablv mount-ed.

In testimony whereof I hereunto aflix my slgnature.

adjustably engaged FRANCOIS o. BRADLEY, 

